Method of extracting lipids from nacreous mollusks

ABSTRACT

The method of extracting a lipidic active principle from a solid material coming from a nacreous mollusk comprises the steps of grinding the nacre into a fine powder, preferably having a mean grain size of less than 20 μm, of putting the powder into contact with a lipid solvent, of separating the solvent, and of extracting the lipidic active principle by evaporating the solvent.

The present invention relates to a method of extracting an activeprinciple coming from nacreous mollusks, and to a method of extractingthe active principle.

BACKGROUND OF THE INVENTION

In order to regenerate the cutaneous barrier of the skin, it is known,in particular from document FR-A-1 350 038, that is it desirable totreat the skin with regenerative cosmetic compositions containing anactive principle that is rich in lipids, in particular polar lipidsextracted from the flesh of nacreous mollusks, in particular from oysterflesh. The extraction processing is complex since it is necessary tobegin by grinding the flesh, either after drying it, or else afterdehydrating it. The processing is therefore expensive. In addition, theflesh of nacreous mollusks is suitable for food applications for humansor animals, such that the raw material is itself of non-negligible cost.

OBJECT OF THE INVENTION

An object of the invention is to propose a method enabling an activeprinciple to be extracted from a nacreous mollusk at lower cost.

DETAILED DESCRIPTION OF THE INVENTION

A method is proposed of extracting an active principle coming fromnacreous mollusks, the method comprising the steps of separating thenacre from the remainder of the shell of a nacreous mollusk, of grindingthe nacre into a fine powder, preferably having mean grain size of lessthan 20 micrometers (μm), and more particularly mean grain size of about8 μm, of performing lipid extraction on the resulting powder bysubjecting it to a lipid solvent, and then of extracting the activeprinciple from the solvent.

Lipid extraction can be performed using any known method such as, forexample, subjecting the powder to a lipid solvent such as a mixture ofchloroform and methanol, or hot ethanol, and then separating bycentrifuging to separate a solid phase from a liquid phase, followed byeliminating the solvent from the liquid phase by evaporation. Theresulting active principle is in the form of a brown gel that can beused directly in the cosmetic composition of the invention. In practice,by using nacre powder having a mean grain size of about 8 μm, about 5kilograms (kg) of active principle are obtained from one (metric) tonneof nacre. In this context, it should be observed that nacre is a solidthat is easy to grind so the processing is inexpensive. In addition,oyster shells constitute waste that is almost worthless, such that theinvestment for purchasing the raw material can be considered as beingzero.

The active principle as obtained in this way is mixed with aconventional cosmetic medium in a proportion of at least 0.2%, andpreferably 0.5% to 1% by volume or by weight, depending on the intendedapplication.

Naturally, the invention is not limited to the embodiment describedabove and can be implemented in various ways without thereby goingbeyond the ambit of the invention as defined by the claims.

In particular, although provision is made above for nacre to be groundto a mean grain size of about 8 μm, it is possible to grind less finely,so as to obtain a mean grain size that is preferably less than 20 μm,with the extracted yield decreasing with coarser grinding.

Although the invention is described as using nacre coming from an oysterof the genus Pinctada, species margaritifera, it is possible not only touse oysters of a different genus or a different species, but also to useother nacreous mollusks.

It is also possible to proceed with lipid extraction from a mixture ofpowder coming from the body and from the nacre of the same mollusk or ofmollusks that are different from one another, in particular when ananalysis of the resulting active principles reveals differences thatshow it is useful to make a combination.

1. A method of extracting a lipidic active principle from a solid material coming from a nacreous mollusk, the method comprising the steps of grinding the nacre into a fine powder, of putting the powder into contact with a lipidic solvent, of separating the solvent, and of extracting the lipid active principle by evaporating the solvent.
 2. The method according to claim 1, wherein the nacre is ground to a powder having a mean grain size of less than 20 μm.
 3. The method of extracting lipids according to claim 2, wherein the nacre is ground to a powder having a mean grain size of about 8 μm.
 4. The method according to claim 1, wherein the nacre comes from oysters of the genus Pinctadaspecies margaritifera. 